Chapter 6.5, Problem 11E

Solution

To Find: The error and then correct in the given statement.

The study is randomized comparative experiment.

Given information: A company’s researchers want to check the effects of adding shea butter in the existing hair conditioner of the people. Total $100$ people are selected as volunteers and $50$ are randomly selected in one group who uses existing hair conditioner and the other $50$ are selected in one group who uses shea butter in hair conditioner.

Calculation:

Randomized comparative experiment is the one in which people are chosen randomly in the group and both groups are under same condition except one which is being studied. In this, biasness gets eliminated whereas, in the comparative observational study the people are observed without hampering them or their environment.

Hence, the error is that it is not comparative observational study. The given study is randomized comparative experiment.